Locking construction for paperboard cartons



March 21, 1961 o. w. STONE LOCKING CONSTRUCTION FOR PAPERBOARD CARTONS Filed June 24, 1957 2 Sheets-Sheet 1 II E a 4L INVENTOR.

ORISON w. STONE ATTORNEYS.

March 21, 1961 0. w. STONE LOCKING CONSTRUCTION FOR PAPERBOARD CARTONS Filed June 24, 1957 2 Sheets-Sheet 2 m lrlrl Ulla an E HUEUEE INVENTOR. ORiSON W. STONE ATTORNEYS.

United; 9

LOCKING CONSTRUCTION non PAPERBOARD CARTONS Filed June 24, 1957, Ser. No. 667,494

1 Claim. (Cl. 206-65) The invention relates to a locking tongue and slot construction for the overlapping flaps of a wrap-around paperboard carton for packaging canned goods.

Ordinary tongue and slot locking devices sometimes slip and allow a wrap-around carton band to become loosened. This can be particularly troublesome in using this type of carton for the packaging of products contained in tin cans, because loosening of the package may allow the cans to become disengaged and fall out of the open ends of the carton. I have discovered how to prevent, or minimize the extent of, slippage between the tongue and slot as employed for locking the overlapping ends, or end flaps, of a wrap-around carton band for packaging goods contained in cans arranged in parallel rows. According to my invention, the locking tongue of one flap is foldable about a line at the base of the tongue aligned with an edge of the slot in the other flap when the flaps are in closed position, in which position the tongue and slot are adjacent the space between four of the cans. The tongue has locking ears which extend beyond the ends of the slot and which, after the tongue has been pushed inwardly through the slot, extend into engagement with adjacent sides of the cans. This engagement of the locking tongue with the sides of the cans 'holds the tongue in a position projecting downwardly between the containers and thereby assists in preventing slippage between the tongue and slot and consequent loosening of the package. Also, the locking ears of the tongue form shoulders for engagement with the chines of the cans to assist further in preventing slippage between the tongue and slot.

With reference to the accompanying drawings, I shall now describe the best mode contemplated by me for carrying out my invention.

Fig. 1 is a face view of the inside of a carton blank embodying my improved locking arrangement.

Fig. 2 is a side elevational view showing the carton being wrapped around the cans.

Fig. 3 is a top plan view of the package. One of the two locking tongues has been pushed through its slot, the other not.

Fig. 4 is an enlarged detail view, in vertical cross section on the line 44 of Fig. 3, showing how the shoulders of the locking ears of the tongue engage the chines of the cans.

Fig. 5 is a diagrammatic view, which may be considered as an enlarged vertical cross section on the line 55 of Fig. 4, illustrating how my construction assists in preventing slippage between the tongue and slot.

Fig. 6 is a similar diagrammatic view, illustrating the possible effects of omitting the special structural features of my locking device.

Fig. 1 shows the blank for a wrap-around paperboard carton for packaging six cans C arranged in two parallel rows of three cans each. In this general type of carton suitable means are provided for holding the cans in place once the carton has been wrapped tightly around them, but, as such can-holding means are well known in the tates atent 2,975,891 Patented Mar. 21, 1961 art, it will be unnecessary to described them here. The ends of the carton band terminate in overlapping flaps 7 and 8. A slot, or slots 9 in one of the flaps cooperates with a complementary tongue, or tongues 10, in the other. Once the carton band has been wrapped around the cans in the manner indicated in Figs. 2 and 3, the tongues, which are wider than the slots, are pushed through the slots. The tongue 10 at the top of Fig. 3 is ready to be pushed through the slot; that at the bottom of the same figure has been pushed through.

Each of the locking tongues 10 is foldable about a score line 11 at the base of the tongue aligned with edge portion 12 of slot 9 when the flaps are in close-d position with the tongue flap 8 above the slot flap 7. In this position (Fig. 3) the tongue and slot are adjacent the space between hour of the cans. The tongue has locking ears 13 (Fig. 4) which extend beyond the ends 14 of the slot and which, after the tongue has been pushed inwardly through the slot, extend into engagement with the sides of the cans so as to hold the tongue in a position projecting downwardly between the containers (Figs. 3 and 4) and thereby assist in preventing slippage between the tongue and slot and consequent loosening of the package. The locking ears are formed with shoulders 15 for engagement with the chines 16 of the cans to assist further in preventing slippage between the tongue and slot. How this is accomplished will now be explained with reference to Fig. 5.

In Fig. 5, we see the tongue 10 with its locking ears in engagement with the left-hand container C. This holds the tongue against springing back toward the plane of the flaps 7 and 8, and helps keep the tongue from being pulled out of its alignment with the edge 12 of the slot. The forces tending to pull the flaps 7 and 8 apart in the directions of the arrows F and F thus are resisted by a bearing of the surface of the tongue against the whole side 12 of the slot instead of just by the engagement between the edges of ears 13 and the ends- 14 of the slot. With this arrangement, which takes the tearing load oif the locking ears and slot ends, there is much less tendency to tearing and distortion such as otherwise would permit the package to become loosened. As seen in Fig. 5, forces F and F may be considered to be resisted at R by the force of reaction at edge 12 of the slot, acting in conjunction with the force of reaction at R where the tongue bears against the sides of the cans. R and R produce a couple resisting the torque tending to rotate tongue 10 in a clockwise direction. If permitted to rotate into a position such as shown at 10 in Fig. 6, the tongue would lose much of its locking eflectiveness. Its movement into position 10" is resisted further by engagement between shoulders 15 of the tongue andchines 16 of the cans. The result is to maintain the full overlap between flaps 7 and 8 of the carton, as diagrammatically suggested by vertical alignment of given points a and b of the flaps. Fig. 6 illustrates the possible efiects of omitting the special structural features I have described. Notice that here the flaps 7 and- 8 have pulled apart to the extent suggested by vertical nus-alignment between the given points a and b of the flaps. Resistance to pulling the flaps apart is no longer furnished by a bearing of the surface of the tongue against the side 12 of the slot because the unforestalled upward movement of the tongue has allowed the base of the tongue to pull up over the side of the slot, throwing the locking burden entirely upon the edges of locking ears or upon whatever other secondary attachment may have been provided.

The terms and expressions which I have employed are used in a descriptive and not a limiting sense, and I have no intention of excluding such equivalents of the I invention described, or of portions thereof, as fall within the scope of the claim.

I claim:

A carton package comprising a paperboard carton wrapped around goods contained in cylindrical containers such as metal cans having chines, said containers arranged in parallel rows within the carton, said carton having overlapping flaps, a slot in one of the flaps and a complementary locking tongue in the other flap, the locking tongue and slot positioned adjacent the space between four of the cylindrical containers and the locking construction being-characterized as follows: the locking tongue extending inwardly of the package at nearly a right angle to the flaps and having positioning ears extending laterally from each side thereof between adjacent pairs of said four containers, said positioning ears 5 engaging the chines of at least two adjacent containers.

References Cited in the file of this patent UNITED STATES PATENTS 10 2,597,848 Reeser May 27, 1952 2,786,572 Gentry Mar. 26, 1957 2,867,320 Andre Jan. 6, 1959 

